Magnetothermoelectric figure of merit of Co/Cu multilayers

Abstract

The switching of the magnetization configurations of giant magnetoresistance multilayer stacks not only changes the electric and thermal conductivities, but also the thermopower. We study the magnetotransport and the magneto-thermoelectric properties of Co/Cu multilayer devices in a lateral thermal gradient. We derive values of the Seebeck coefficient, the thermoelectric figure of merit, and the thermoelectric power factor. The Seebeck coefficient reaches values up to -18 µV/K at room temperature and shows a magnetic field dependence up to 28.6 % upon spin reversal.In combination with thermal conductivity data of the same Co/Cu stack, we find a spin dependence of the thermoelectric figure of merit of up to 65 %. Furthermore, a spin dependence of the power factor of up to 110 % is derived.

Tailoring magnetic properties in arrays of pulse-electrodeposited Co nanowires: The role of Cu additive

“…So far, single element, binary alloy, ternary alloy and multilayered magnetic NWs such as Co, Ni, Fe, NiCu, FeCo, CoCu, CoNi, FeCoCu and CoNi/Cu have been prepared using the electrodeposition technique [12][13][14][15][16][17][18][19][20]. Having paid particular attention to both the binary alloy and multilayered NWs due their potential application in the magnetoresistive and thermoelectric devices at the nanoscale, they show considerable amounts of magnetoresistance and magnetothermopower, which in turn, can compete with those of the conventional counterpart materials [18,20,21].…”

Magneto-Seebeck effect in spin-valve with in-plane thermal gradient

“…[11][12][13] It has been predicted that this spin current can be used to even switch the magnetization of a nano-magnet via the spin-transfer torque effect. 14,15 Spin-dependent Seebeck effect has been investigated in magnetic multi-layers [16][17][18][19][20] and recently in magnetic tunnel junction pillers. [21][22][23][24] The reciprocal effect, viz., spin-dependent Peltier effect has also been reported.…”

Electrochemical synthesis of magnetic nanowires with controlled geometry and magnetic anisotropy

“…Measurements performed at 0°with respect to the wire's axis indicate a flipping behavior for the Co/Cu nanowires with thick and thin Cu segments, whereas an intermediate Cu thickness (1.5 nm) led to a competition between flipping and rotation, which was ascribed to the strong exchange coupling between Co layers. Because of the outstanding GMR effects displayed by Co/Cu multilayered nanowire arrays, they have more recently been explored as good candidates for exhibiting magnetothermoelectric and high thermopower effects (Hu et al, 2014).…”